Evolutionary genetics of genital size and lateral asymmetry in the earwig Euborellia plebeja (Dermaptera: Anisolabididae)
Evolutionary genetics of genital size and lateral asymmetry in the earwig Euborellia plebeja (Dermaptera: Anisolabididae)
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DOI：
10.1111/j.1095-8312.2010.01491.x
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发表时间：
2010-09-01
影响因子：
1.9
通讯作者：
Iwase, Ryota
中科院分区：
文献类型：
--
作者：
Kamimura, Yoshitaka;Iwase, Ryota
雄性外生殖器显示出几个进化特征，包括密切相关的物种之间的快速形态分化和低物种内表型变异。此外，尽管昆虫的外部形态基本上是两侧对称的，但生殖器不对称是普遍存在的。一些假说，如性选择和锁和钥匙假说，已被提出来解释这些特征的生殖器进化。虽然这些假说提供了不同的预测生殖器的变异的遗传基础，详细的定量遗传研究已经进行了只有三个昆虫类群：异翅类，金龟子（金龟子科），果蝇。对于一个anisolabidid earwig，Euborellia plebeja，其特点是成对的细长的intromittent器官，我们估计的遗传力和遗传相关性的生殖器偏侧，生殖器的大小，和身体大小。没有统计学上显着的加性遗传，显性，母体，或共同的环境影响，检测到生殖器偏侧（准备使用左侧或右侧intromittent器官）。这一结果进一步支持了反对称变异的方向是由非遗传因素随机决定的一般规律。与其他昆虫相比，尽管生殖器的表型变异有限（异速生长斜率< 1），但这两个性状表现出相似的遗传变异水平，以狭义遗传力（h2）和加性遗传变异系数（CVA）衡量。比较表明，种间遗传变异/相关结构的差异的原因是发育过程（全或半代谢）和/或模式的性选择。(C)2010年，伦敦林奈学会，林奈学会生物学杂志，2010年，101，103-112。
Male genitalia show several evolutionary characteristics, including rapid morphological divergence between closely related species and low within-species phenotypic variability. In addition, genital asymmetry is widespread despite the essentially bilaterally symmetric external morphology of insects. Several hypotheses, such as sexual selection and lock-and-key hypotheses, have been proposed to explain these characteristics of genital evolution. Although these hypotheses provide different predictions about the genetic basis of variation in genitalia, detailed quantitative genetic studies have been conducted in only three insect taxa: heteropterans, dung beetles (Scarabaeidae), and drosophilid flies. For an anisolabidid earwig, Euborellia plebeja, characterized by paired elongated intromittent organs, we estimated the heritabilities and genetic correlations of genital laterality, size of genitalia, and body size. No statistically significant additive genetic, dominance, maternal, or common environmental effects were detected for genital laterality (readiness to use either the left or the right intromittent organ). This result lends further support to the general rule that the direction of antisymmetric variations is randomly determined by non-genetic factors. Irrespective of the restricted phenotypic variation in genitalia compared with body size (allometric slope < 1), as observed in previous studies for other insects, these two traits showed a similar level of genetic variation, measured as the narrow sense heritability (h2) and the coefficient of additive genetic variation (CVA). Comparison suggests the causes of interspecific differences in genetic variability/correlation structures were developmental processes (holo- or hemimetabolous) and/or mode of sexual selection. (C) 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 101, 103-112.